Medical textiles are often used in surgeries where tissues need to be covered, connected, or held in place, which is common in sports medicine, as well as cardiovascular, orthopedic, bariatric, and cosmetic surgeries, among others. Soft tissue repair surgeries are extremely common as every year there are an estimated 1 million hernia repair surgeries, 300,000 pelvic organ prolapse repairs, 260,000 stress urinary incontinence surgeries, 300,000 breast reconstructions/augmentations, and ˜55,000 rotator cuff repairs in the United States. The most prominent examples of treatments that depend on medical textiles include hernia repair, in which a textile can hold protruding tissue in place, aortic grafts to repair blood vessels, artificial skin grafts to cover burnt skin, braces to immobilize sprained ankles, and compression stockings or hosiery to improve circulation. Mesh (typically knitted/woven synthetic polymer) is commonly used to mechanically support tissue as it heals and to reduce injury recurrence rates because it can allow for a tension-free repair.
Many patients suffer serious complications after mesh implantation, as existing meshes can weaken and irritate body tissues. For example, 25% of abdominal hernias recur within three years because mesh migrates or abdominal tissue does not heal, up to 43% of hernia patients experience chronic pain, and 10% of hernia patients suffer infections requiring mesh replacement. Many complications are caused by mismatches between mesh, which is typically flat with a uniform mechanical stiffness, and human tissue, which can have great variation in properties such as curvature, stiffness, and direction of motion within a single patient, and across similar locations for different patients. Items worn on or in the human body, ranging from clothing and eyeglasses to prostheses and medical implants, typically are fitted to the person that wears it for the item to be effective for that individual. Similarly, meshes work better, whether in terms of comfort, aesthetics, or other function, when their geometry is tailored to the user. Currently, such tailoring is accomplished by: 1) producing various standard sizes; 2) making the device size adjustable, for example through clasps or straps; and 3) by bespoke tailoring, where these items are individually handmade to measurements of a person. The first two of these only imperfectly approximate different body shapes, while bespoke tailoring is prohibitively expensive for the vast majority of applications.
Three-dimensional (“3D”) printing is growing in popularity as a way to produce objects, including but not limited to medical implants. There are multiple known techniques for printing three-dimensionally, such as non-extrusion based processes like stereolithography and PolyJet processing, and extrusion-based processes like fused deposition modeling (FDM). While these techniques do offer benefits, such as allowing for high resolution printing, they suffer from a number of shortcomings as well. For example, many objects printed using known, traditional 3D-printing techniques produce parts that have significantly poorer mechanical properties than those produced by traditional fiber composite manufacturing processes. This is at least because the existing 3D-printing techniques are not as adaptable or configurable to easily provide a variety of properties across a surface area of the printed object (e.g., it is difficult to change the strength and/or flexibility of a printed object across a surface area of the object). Most 3D-printing materials are either hard and stiff, and thus difficult to conform to surfaces and uncomfortable to wear, or they are mechanically fragile. The latter is true particularly for materials printed that are intended to be biocompatible, such as hydrogels (˜200 kPA tensile strength).
One example of a 3D printing technique that does not provide strength and flexibility that is often desirable for an object to have is a technique known as selective laser sintering (SLS). During an SLS printing process, a roller distributes powder in layers that are then partially melted by a laser to induce bonding in a pattern. This process can print metals and is relatively rapid, but its mechanical properties tend to be relatively poor due to residual thermal stresses and porosity, as well as the machines being relatively expensive to buy and run.
Additive manufacturing generally refers to manufacturing a part by adding material as opposed to subtracting, and thus is a way by which parts can be printed three-dimensionally. Additive manufacturing techniques include some of the aforementioned techniques (e.g., FDM), as well as others, such as fused filament fabrication (FFF). This technique is different from other 3D-printing techniques because it allows deposited material to be added on top of and bonded to previously deposited material rather than relying upon an existing mold or subtracting material from a mass of material to produce a 3D-object. Additive manufacturing is growing in popularity as a 3D-printing technique because it allows users to create unique geometries and process unique material compositions. However, even existing additive manufacturing 3D-printing techniques are limited in their ability to print a variety of materials, at a desirable manufacturing rate, and at a desirable manufacturing cost. Further, even existing additive manufacturing 3D-printing techniques suffer from similar deficiencies as other 3D-printing techniques when it comes to printing objects that are adaptable or configurable to easily provide a variety of properties across a surface area of the printed object. For example, even using existing additive manufacturing 3D-printing techniques, it is still difficult to change the strength and/or flexibility of a printed object, such as a surgical mesh, across a surface area of the object. Generally, fabrics and the like produced using existing additive manufacturing 3D-printing techniques are of significantly poorer quality than those produced by traditional fiber compositing manufacturing processes. This is at least because existing additive manufacturing 3D-printing techniques result in poorer molecular alignment along a fiber axis and issues related achieving strong inter-layer bonding. Still further, additively manufactured parts typically have a relatively homogenous structure, most simply featuring isotropic or uncontrolled anisotropic bonding, which makes parts brittle and stiff, and thus unsuitable for wear.
Accordingly, there remains a need to improve methods, systems, and devices for producing 3D-printed parts that allow the parts to be printed to have a desirable strength and flexibility, thereby allowing the printed parts to be adaptable or customizable as desired. While the present disclosures are by no way limited to 3D-printed parts in the medical field, within that field there is a need for improved methods, systems, and devices for producing 3D-printed medical components (e.g., medical textiles and medical implants), by way of non-limiting example, surgical meshes for soft tissue repair surgeries, that have a desirable strength and flexibility for use in various surgical procedures and that can be customized and configured based on the needs of a patient and/or surgical procedure, and/or the preferences of a surgeon or other clinician.